From 56e890cec0a28c0a485212ccebfaf774235a79a2 Mon Sep 17 00:00:00 2001
From: Thomas Schmucker <ts@its1.de>
Date: Wed, 3 Jan 2024 23:35:54 +0100
Subject: prepare for more puzzles ... :)

---
 src/day25.cpp | 140 ----------------------------------------------------------
 1 file changed, 140 deletions(-)
 delete mode 100644 src/day25.cpp

(limited to 'src/day25.cpp')

diff --git a/src/day25.cpp b/src/day25.cpp
deleted file mode 100644
index 1d5e19e..0000000
--- a/src/day25.cpp
+++ /dev/null
@@ -1,140 +0,0 @@
-#include <algorithm>
-#include <array>
-#include <fstream>
-#include <iostream>
-#include <map>
-#include <queue>
-#include <random>
-#include <set>
-#include <sstream>
-#include <string>
-#include <string_view>
-#include <vector>
-using namespace std;
-
-using graph_type = map<string, set<string>>;
-
-vector<string>
-split(const string& line, char sep)
-{
-	vector<string> parts;
-	stringstream   input{ line };
-
-	for ( string part; getline(input, part, sep); ) {
-		parts.emplace_back(part);
-	}
-
-	return parts;
-}
-
-graph_type
-read_file(string_view filename)
-{
-	fstream    input{ filename };
-	graph_type graph;
-
-	for ( string line; getline(input, line); ) {
-		const auto components = split(line.erase(line.find(':'), 1), ' ');
-
-		for ( size_t i = 1; i < components.size(); ++i ) {
-			graph[components[0]].insert(components[i]);
-			graph[components[i]].insert(components[0]);
-		}
-	}
-
-	return graph;
-}
-
-bool
-bfs(graph_type graph, const string& source, const string& dest, function<void(const string&, const string&)> visit) // NOLINT
-{
-	set<string> visited;
-
-	queue<string> queue;
-	queue.emplace(source);
-
-	while ( !queue.empty() ) {
-		auto candidate = queue.front();
-		queue.pop();
-
-		if ( candidate == dest ) {
-			return true;
-		}
-
-		for ( const auto& neighbour: graph[candidate] ) {
-			if ( !visited.contains(neighbour) ) {
-				queue.emplace(neighbour);
-
-				visit(candidate, neighbour);
-				visited.emplace(neighbour);
-			}
-		}
-	}
-	return false;
-}
-
-auto
-random_node(const graph_type& graph)
-{
-	static random_device dev;
-	static mt19937       generator(dev());
-
-	uniform_int_distribution<graph_type::size_type> distribute(0, graph.size()-1);
-
-	auto iter = graph.begin();
-	advance(iter, distribute(generator));
-	return iter->first;
-}
-
-void
-part1(graph_type graph)
-{
-	map<tuple<string, string>, int> frequencies;
-	for ( size_t idx = 0; idx != 2; ++idx ) {
-		for ( const auto& second: graph ) {
-			bfs(graph, random_node(graph), second.first, [&](const string& candidate, const string& neighbour) {
-				if ( candidate < neighbour ) {
-					frequencies[make_tuple(candidate, neighbour)]++;
-				}
-				else {
-					frequencies[make_tuple(neighbour, candidate)]++;
-				}
-			});
-		}
-	}
-
-	vector<tuple<tuple<string, string>, int>> sorted_frequencies{ frequencies.begin(), frequencies.end() };
-
-	sort(sorted_frequencies.begin(), sorted_frequencies.end(), [](const auto& lhs, const auto& rhs) {
-		return get<1>(lhs) > get<1>(rhs);
-	});
-
-	sorted_frequencies.erase(sorted_frequencies.begin() + 3, sorted_frequencies.end());
-
-	for ( const auto& link: sorted_frequencies ) {
-		const auto [left, right] = get<0>(link);
-
-		graph[left].erase(right);
-		graph[right].erase(left);
-	}
-
-	auto reachable = [&graph](const string& start_node) {
-		set<string> nodes;
-		bfs(graph, start_node, "", [&nodes](const string& candidate, const string& neighbour) {
-			nodes.insert(candidate);
-			nodes.insert(neighbour);
-		});
-		return nodes.size();
-	};
-
-	const auto [left, right] = get<0>(sorted_frequencies[0]);
-
-	cout << reachable(left) * reachable(right) << endl;
-}
-
-int
-main()
-{
-	auto graph = read_file("data/day25.txt");
-	part1(graph);
-}
-- 
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